The present invention relates generally to an apparatus for installing condition-sensing mechanisms in remote locations, and more particularly to such an apparatus for installing strain gages and the like at selected locations within a wellbore penetrating a subterranean earth formation.
The recovery of energy values contained in subterranean earth formations, such as gas and oil-bearing sandstone and shale, geothermal formations, coalbeds and the like, is frequently achieved by penetrating the energy-bearing strata with strategically placed wellbores. In the recovery of these energy values through the wellbores such as achieved by the in situ combustion of coal and the primary through tertiary recovery of petroleum products, it is often desirable to monitor various conditions occurring in the subterranean earth formation which may in some manner affect the efficiency of the recovery operation. For example, the presence of strain gages in the subterranean earth formation would be of considerable value to measure strain such as caused by subsidence, formation shifting, pressure variations, or strains such as caused by the injection of fluids for enhanced oil recovery purposes or for fracturing the earth formation and monitoring effects of the same in adjacent wellbores. The monitoring of strain, temperature and pressures in subterranean earth formations is of considerable value in the recovery of energy values. For example, installing such transducers either in the "open" uncased wellbore or on the casing can be useful in evaluating research or production reservoirs through various tests. As another example, the early detection of potentially deleterious conditions in the strata adjacent the wellbore can be utilized to prevent the loss or downtime of the wellbore due to the fracturing of the casing or the displacement or breakage of other equipment contained within the wellbore. Also fracturing pressures, casing stability in situ stress and strain and their gradient changes from either local wellbores or regional activities, such as mining or fluid production or injection can be closely monitored to increase the efficiency of the energy recovery operation.